The possible role of humans in the early stages of machair evolution: palaeoenvironmental investigations in the Outer Hebrides, Scotland
- ISSN: 03054403
- DOI: 10.1016/j.jas.2004.09.011
Low altitude sandy plains (machair) are a distinctive feature of the Atlantic coasts of the Scottish Outer Hebrides. They formed as a result of shoreward movement of sediment consequent upon a rise in Holocene sea levels. During the long period over which machair has been forming, the earliest date proposed for their human occupation is the Neolithic. The natural origins of the machair are not disputed, but examination of deposits at sites in the islands of Benbecula and Grimsay encourages us to advance a possible anthropogenic role in the process of machair development, and also to suggest that human involvement may date from the Mesolithic period (pre-5000 BP ca. 5730 cal BP), a time for which archaeological evidence is lacking from the Outer Hebrides. The presence of charcoal might suggest that burning of the vegetation cover of the machair was an additional factor to the supposedly dominant marine and aeolian processes in sand mobility. Removal of shrub vegetation may also have left sand surfaces open to deflation. There remains a difficulty in separating natural from human causes in investigations of long-term coastal evolution.